Scott Penrose

Arduion Pull up resistors

Scott is an expert software developer with over 30 years experience, specialising in education, automation and remote data.

Don't use them. It is built into most chips, but you have to enable it. (works Arduino AVRs; Teensy)

Older versions of arduino you simply did:

 pinMode(4, INPUT);
 digitalWrite(4, HIGH);

News versions

  pinMode(4, INPUT_PULLUP);

  • Arduino